I'm thinking of just going single turbo right off the bat with my 2jz swap. With the Greddy T88 kit, would I have to dent in my firewall or do any other modifications? And I'd also like to do a full custom 4 in. exhaust. 4 in. down pipe, high flow cat, 4 in. mid pipe, 4 in. up pipe, and come out to dual Apex'i N1 tip's. This sound like a nice idea?